Electron Material Glyph not visible at runtime

Delphi 10.3 / TMS WebCore latest release

Hello,

during design time, the selected Material Glyph is visible on my TWebBitButton, but not when I start the Electron App. In the project settings - JavaScript libraries, I added the Google Material

JavaSriptLibraries

Bundle the material font with your Electron app.
It should be on your system:
C:\Windows\Fonts\MaterialIcons-regular.ttf

That did not work. In a test PWA application its working as expected.

Cannot reproduce.

Test project attached.
Project1.zip (402.6 KB)

With a fresh created electron project and Google-Material Icon library attached its working. Don't know what broke in my old app. To load the icons the app needs an internet connection, is that right? How to attach the icon library local?

Thank you, I should figure that out by myself - sorry to waste your time :-)